US Bridges

SH 75 over Big Wood River

Fair

Blaine County, Idaho · 0.6 S. Ketchum Scl · Structure no. 000000000017671

Built
2017
8 years old
Condition
Fair
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
231 ft
2 main spans
Daily traffic
14,500
2023 count
Owner
State
State Highway Agency

About this bridge

SH 75 over Big Wood River is a prestressed concrete stringer/multi-beam or girder carrying SH 75 over Big Wood River in Blaine County, Idaho. It was built in 2017, so it is 8 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 14,500 vehicles a day, roughly 7% of them trucks, projected to reach 21,750 by 2042. The structure is 231 ft (70.4 m) long and 74 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesSH 75
CrossesBig Wood River
Location0.6 S. Ketchum Scl
RouteState Highway 75
CountyBlaine County
StateIdaho
Coordinates43.65369, -114.34886
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating53.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHL 93
Structure length231 ft (70.4 m)
Longest span80 ft (24.4 m)
Deck width74 ft (22.6 m)
Roadway width71 ft (21.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,500 (2023)
Projected traffic21,750 by 2042
Trucks7%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 75 over Big Wood River built?

It was built in 2017, making it 8 years old in 2025.

What condition is SH 75 over Big Wood River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in July 2024.

How much traffic does SH 75 over Big Wood River carry?

About 14,500 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is SH 75 over Big Wood River?

The structure is 231 ft (70.4 m) long with a longest span of 80 ft (24.4 m) and a deck 74 ft wide.

Who owns SH 75 over Big Wood River?

It is owned by the State Highway Agency.